Basic concepts for the analysis of polycyclic aromatic hydrocarbons (PAHs) and NSO-heterocycles were developed within the framework of the KORA project. However, most of the results presented here that relate to the efficiency of activated carbons in Permeable reactive barriers (PRBs) to remediate NSO-heterocycles were obtained within Subproject 3 of RUBIN II. The composition was chosen in such a way that two aromatic hydrocarbons, phenol as the prototype of a phenolic compound, and three NSO-heterocycles were present in the mixture. The knowledge of adsorption processes of mixtures on the activated carbon is important in the remediation of aromatic compounds in a PRB. The efficiencies of two PRBs in Karlsruhe (Germany) and Brunn am Gebirge (Austria) were investigated with respect to the adsorption of PAHs, phenols, NSO-heterocycles, benzene, toluene, ethylbenzenes and xylens, and related compounds in four field campaigns. Analytical methods and extraction procedures were developed to investigate a complex spectrum of aromatic compounds that are typically found in groundwater samples.